Combination bulb-piston syringe

ABSTRACT

A piston-type irrigating syringe, in which the piston shaft, slidable in the syringe barrel with the resilient piston, is hollow and extends into and communicates with an integral resilient hollow bulb and in which the resilient piston has a restricted passage providing continuous communication between the hollow shaft and bulb and the barrel and nozzle opening of the syringe, whereby the suction and positive pressures applied to a body cavity are applied gradually at a controlled rate and can be varied over a wide gradient, as compared to standard bulb-type syringes and standard piston-type syringes, whereby such pressures and suctions can be controlled to avoid harmful effects, whereby the necessity of employing more than one kind of syringe, i.e., a bulb-type syringe for mild pressures and suctions and a piston-type syringe for greater pressures an suctions, is avoided, whereby the fluid reservoir capacity is greatly increased over standard syringes, and whereby greater maximum suctions and pressures can be achieved compared to standard syringes.

United States Patent Ericson [54] COMBINATION BULB-PISTON SYRINGE [72] Ilnventor: Richard E. Ericson, Keene, NH.

[73] Assignee: Elliot Laboratories, Inc., Fitzwilliam, NH.

[22] Filed: Mar. 23, 1970 [211 App]. No.: 21,737

[52] U.S.Cl .,.....l28/231,128/234,128/220 [51] Int. Cl. ..A61m 1/00.[58] Field olSearch ..l28/231,234,224, 225,218, 128/220, 227, 228, 233,216, 235, 236, 237, 238

[56] References Cited UNITED STATES PATENTS 1,643,531 9/1927 Wolf..128/220 2,841,145 7/1958 Epps.. ..128/218 2,735,735 2/1956 Abel128/234 X 3,295,523 1/1967 Weichselbaum. ..128/232 822,110 5/1906Gaillot ..l28/220 2,869,543 1/1959 Ratcliff et a1. ..l28/234 X 2,532,59812/l950 Boegei' ..l28/234 3,291,128 12/1966 O'Neil ..l28/234 X PrimaryExaminer-Richard A. Gaude't Assistant Examiner-J. Yasko Att0rneyW.Saxton Seward [57] ABSTRACT A piston-type irrigating syringe, in whichthe piston shaft, slidable in the syringe barrel with the resilientpiston, is hollow and extends into and communicates with an integralresilient hollow bulb and in which the resilient. piston has arestricted passage providing continuous communication between the hollowshaft and bulb and the barrel and nozzle opening of the syringe, wherebythe suction and positive pressures applied to a body cavity are appliedgradually at a controlled rate and can be varied over a wide gradient,as compared to standard bulb-type syringes and standard piston-typesyringes, whereby such pressures and suctions can be controlled to avoidharmful effects, whereby the necessity of employing more than one kindof syringe, i.e., a bulb-type syringe for mild pressures and suctionsand a piston-type syringe for greater pressures an suctions, is avoided,whereby the fluid] reservoir capacity is greatly increased over standardsyringes, and whereby greater maximum suctions and pressures can beachieved compared to standard syringes.

2 Claims, 4 Drawing Figures Jan. 18, 1972* COMBINATION BULB-PISTONSYRINGE SUMMARY OF INVENTION This invention relates to a combined bulband piston-type medical irrigating syringe for irrigating body cavitiesand wounds.

There are two basic types of irrigating syringes presently being used bythe medical profession.

One is the conventional bulb-type syringe for mild irrigations employinga flexible, resilient bulb at the end of a hollow syringe stem. Thesyringe is used to irrigate body cavities such as the urinary bladder,or wounds during surgery, by alternately squeezing and releasing thebulb to expel irrigating fluid out of the syringe and into the cavity orwound and to aspirate such fluid into the syringe and out of the cavityor wound, respectively, in a conventional manner. As used herein,including the claims hereof, the word bulb" refers to any chamberconnected to the hollow syringe stem, usually at the end opposite thesyringe nozzle, and having a resilient, flexible and squeezable wall,whereby the volume of the chamber can be changed to provide a pumpingaction to expel a fluid from, and drain or aspirate a fluid into, thesyringe. It includes not only the conventional rounded enlarged flexibleand resilient bulb but also a cylindrical flexible and resilientenlargement or an accordion type bellows or even a nonenlarged flexibleand resilient extension of the syringe stem.

The second type of conventional syringe is the piston or plunger-typesyringe. This is used for relatively strong irrigations where greaterforce is required. This type of syringe comprises a conventional syringebarrel, usually rigid, containing a rubbery piston which is inperipheral sealing, but slidable, contact with the internal barrel walland which is moved axially within the barrel by a solid piston shaftsecured thereto to expel irrigating fluid from the barrel into the bodycavity or wound and draw it out of the cavity or wound into the barrel.

A serious disadvantage of the bulb-type syringe is that the maximumpressures and suctions which can be developed are often insufficient tocope with obstructions in the body cavity or difficult-to-remove debris,e.g., clots, mucous, calculus, cells, etc., or to cope with requiredflushing in the case of wound irrigations.

Although the piston syringe provides much greater pressures and suctionsto deal with these difficulties, these pressures and suctions, becausethey are positive and direct, are difficult to control and may result inexceeding those pressures and suctions which are safe with resultingpossible serious harmful effects, e.g., rupturing a vascular bed of amucous membrane. For example, in the case of a stubborn obstruction inthe body cavity a solid noncompressible liquid column is apt to be builtup between the obstruction and the piston. In such case, only a slightmovement of the piston into the barrel can build up a dangerously largeforce, which because of the aforesaid solid column of unyielding liquid,is transmitted directly and instantaneously without reduction orcushioning to the body cavity. By the same token, where there is such astubborn obstruction only a slight retraction movement of the piston canprovide a relatively large and dangerous suction force which istransmitted unabated to the body cavity. Although such pressures andsuctions can be controlled to a degree by controlling the rate andmagnitude of movement of the piston, nevertheless this is at best anexceedingly gross control even for those skilled in the art. Aparticular problem often encountered is that upon applying sufficientforce to the piston to build up sufficient pressure or suction todislodge stubborn debris forming an obstruction, when the debris becomesdislodged, a sudden surge of pressure or suction is apt to occur becauseof the difficulty of relieving the force applied to the pistonimmediately upon dislodgement of the debris.

In practice, as a matter of safety, a bulb-type syringe is oftenemployed first and if it is not sufficient, the next step would be touse a piston-type syringe, which necessitates the additional cost,storage, time and handling of two syringes in two operations, therebyadding to the complexity of the procedure, further risk of contaminationand to the inconvenience of hospital personnel and patient.

It is an object of the present invention to provide a medical syringewhich avoids these difficulties. It is a further object of the inventiontoprovide in a single simple, convenient and inexpensive unit, a medicalsyringe which can be used as a conventional bulb-type syringe and as aconventional piston-type syringe to thereby avoid the necessity of usingtwo separate syringes with the aforesaid disadvantages thereof. Inaddition, the syringe of the present invention permits the use of a widegradient of controlled, cushioned, gradually applied median maximumpressures and suctions between the mild pressures and suctions of abulb-type syringe and the greater forceful positive pressures andsuctions of the piston-type syringe, whereby the sudden buildup ofdangerous, excess pressures and suctions upon sudden dislodgement of anobstruction in the body cavity or for any other reason, is avoided.Regardless of the size of the obstruction, and hence the resistance toflow, and regardless of the magnitude and rate of movement of thepiston, the pressures and suctions applied to the body cavity can onlybe built up gradually to a safe maximum, the excess pressures andsuctions which might nonnally be developed under such circumstancesbeing absorbed or cushioned. Only that pressure or suction required todislodge the obstruction is built up gradually, and upon dislodgerment,liquid is ejected into the body cavity vor withdrawn from the bodycavity without substantially exceeding such required pressure orsuction. 0n the other hand, the syringe of the invention can be used toprovide even stronger irrigation than is possible with the piston-typesyringe. In addition, it permits a substantial increase in syringecapacity without increasing the physical size of the syringe.

This is achieved in accordance with the invention by replacing thepiston shaft of the piston-type syringe with a bulb-type syringe havinga hollow stem with the bulb (preferably the bulb and stem are integral)at one end portion and the resilient piston attached to the other endportion and with a passage, preferably a restricted passage or orifice,through the piston providing continuous communication between the barreland nozzle of the piston syringe and the interior of the hollow stem andbulb. Thus, the bulb and stem function as the piston shaft and also as abulb-type syringe, as will be more fully described hereinafter.

DESCRIPTION OF THE DRAWINGS Other objects and advantages of the presentinvention will be apparent from the following description and theaccompanying drawings describing and showing for illustrative purposes apreferred embodiment of the invention.

In the drawings FIG. I is a view in elevation of a syringe embodying thepresent invention.

FIG. 2 is a view in perspective of the syringe in FIG. 1.

FIG. 3 is a view in perspective from another direction of the syringe ofFIG. 2.

FIG. 4 is a section taken along the line 4-4 of FIG. 1.

DETAILED DESCRIPTION With reference to the drawings, 2 is a syringeembodying the present invention and comprising (a) a hollow cylindricalsyringe barrel 4, which is made of arigid transparent plastic, such aspolypropylene, which hasa tapered hollow nozzle tip 5 at one end forminga nozzle opening 7 of restricted cross section and the other open end 9of which is of the same diameter as the internal diameter of the syringebarrel proper, (b) a generally cylindrical, hollow, rubber piston orplunger 6, the periphery of which engages the inner wall of the barrel 4in a fluidtight manner but which is slidable longitudinally in thebarrel to draw fluid into, and expel fluid from, the barrel and (c) apiston or plunger shaft 8, which is secured to the piston 6 for slidingthe piston back and forth in the barrel and which is in the form of ahollow bulb-type syringe 8 of flexible and resilient plastic, such as anethylene-vinyl acetate copolymer, comprising a hollow, cylindrical stem10, removably secured at one end to piston 6 and extending out of theopen end 9 of the barrel and integrally at its other end into a rounded,hollow, flexible and resilient bulb 12 adapted to be squeezed andreleased to, respectively, expel fluid from and draw fluid into the stem10 and bulb 12. The piston 6 and the bulb syringe 8, i.e., the bulb 12and stem 10, are slidable as a unit back and forth within the barrel 4.

The upper end of barrel 4 is provided with a pair of laterally extendinglugs 14 to provide finger holds during operation of the syringe. I

The periphery of the rubber piston 6 has a pair of axially spacedannular sealing ribs 16 and 18, extending laterally from the upper andlower ends thereof, as shown, and compressed into sealing relationshipwith the inside wall of the barrel 4 to form a pair of axially spacedannular fluidtight seals with an annular space 20 formed by the twosealing ribs 16 and 18, the remainder of the periphery of the pistontherebetween and the inner wall of the barrel 4. Thus a double, balancedsealing effect is achieved while still permitting the piston 6 to bereciprocated in the barrel as a unit with the bulb-type syringe 8without difficulty.

The rubber piston 6 is removably secured to the end of the stem 10 bymeans of a radially outwardly extending annular lip 22 at the end of thestem protruding radially from the lower end of a reduced diameter endportion 24 of the stem 10 into an internal, undercut, annular groove 26in the hollow piston 6, with a portion of the piston proper locatedbetween the lip 22 and the ledge 31 formed by the reduced portion 24, asshown in FIG. 4.

Piston 6 has a lower tapered end wall 28 having a central reducedpassage or orifice 30 therein of circular cross-sectional shape andwhich, in the embodiment shown, is of the same diameter as the nozzleopening 7 and is axially aligned with such nozzle opening.

The external lower surface of end wall- 28 commences at the bottom oflower rib l8 and tapers downward and inwardly at 29 to the lower end ofthe orifice 30, as shown. lntemally, the end wall 28 commences at thelower edge of the internal groove 26 (which is located at a heightslightly below the upper rib 16 and substantially above the lower rib18) and tapers downwardly and inwardly at 33 at a steeper inclinationthan the external taper 29, whereby the thickness of the end wall 28diminishes in a radially inward direction.

The taper of the lower external surface 29 of end wall 28 of the piston6 is the same as the taper 35 of the end wall 32 of the syringe barrelso that when the piston is pushed fully into the barrel, the lowersurface 29 of end wall 28 of the piston mates in close contact with theend wall 32 of the barrel along their areas.

The upper end of the bulb 12 is out-of-round slightly at 34 to form aflattened zone for standing the syringe in an upright manner on arelatively flat surface. The flattened zone 34 has a shallow concavity36 therein for locating the thumb (with the index finger and theadjacent finger under the lugs 14) to squeeze the bulb vertically duringuse, to thereby provide a more controlled irrigating action, and also tolocate the thumb for moving the piston into-the barrel.

The syringe is shipped with an internally tapered plastic protective cap(not shown) frictionally but removably secured over the tip 5.

Although the invention is not limited to, any particular dimensions acommercial syringe embodying the invention has the following dimensions:lntemal diameter of barrell 7i? inch, internal length of barrel to thelower end of end wall 32-5 inches, length of tip I )6 inch, diameter ofopening 7 and orifice SO-three-sixteenths inch, internal diameter ofstem-- 1 inch, height of stem-4% inches, diameter of bulb 2% inches,height of piston-eleven/sixteenths inch, thickness of stem wallonethirty-seconds inch, thickness of bulb wall one thirty-seconds onesixty-fourth inch.

The normal diameters of the ribs 16 and 18 are slightly greater than theinternal diameter of the barrel in order to achieve lateral sealingcompression.

The annular juncture 38 of the wall between the bulb 12 and stem 10 isslightly enlarged in thickness as compared to the bulb proper and stemto prevent roll over of the bulb onto the upper end of the stern whenthe bulb is pushed vertically downwardly by the thumb (with the indexfinger and the next adjacent finger under lugs 14) for piston-typeoperation and when it is squeezed downwardly by the thumb (with the samefingers under lugs 14) for bulb-type operation. Also the thickness ofthe bulb wall at the upper end 40 near and where it flattens out, isslightly less than the thickness of the rest of the bulb wall to permitmaximum flexure at this area by squeezing down on the top of the bulbwith the thumb with the index finger and next adjacent finger under thelugs 14, as aforesaid.

The plastic from which the bulb and stem are made can be any plastic orrubber or other elastomer (preferably transparent or translucent) whichpossesses the properties of being highly flexible, highly resilient,elastic and rubbery with a good memory so that when the bulb is squeezedto deform it, it will immediately spring back or recoil to its originalshape when the squeezing pressure is released. Furthermore, it should behighly stable, inert, nontoxic, impervious, resistant to stress crackingand capable of being sterilized. There are a large number of suchplastics and rubbers and combinations thereof which are suitable, suchas silicone rubber, natural. and synthetic rubbers, e.g.,styrene-butadiene copolymer rubber, low density polyethylene,plasticized polyvinyl chloride, ethylenevinyl acetate copolymer,styrene-butadiene thermoplastic elastomers, such as those sold under thetrade name Kratons by Shell Chemical Company, etc.

Also the piston may be made of natural or synthetic rubber, includingstyrene-butadiene, or any of the other plastics from which the stem andbulb are made. However, because it has a substantially greater thicknessit is stiffer, although still elastic, flexible and resilient forsealing purposes.

The piston may be easily secured on and pulled off the end of the stemmerely by snapping the lip 22 into and out of the undercut groove 26.

However, the piston may be integral with the stem, and the bulb may beseparable from the stem. When the bulb is separate from the stem it maybe made from the same or a different material.

Preferably, the stem and bulb unit is injection blow molded.

The barrel 4 may be made of any rigid or semirigid plastic (preferablytransparent or translucent) conventionally used for making syringebarrels, or even glass or metal.

Preferably the barrel is provided with graduation marks and amounts inconventional manner.

The syringe shown in the drawings may be used as a true bulb-typesyringe by squeezing and releasing the bulb 12 with the stem 10 at alltimes pushed fully into the barrel 4 so that tapered end wall 29 is snugagainst the tapered end wall 32 of the barrel. This serves to expelliquid out of and draw liquid into the interior 42 and 46 of the stemand bulb through the nozzle opening 7 and orifice 30.

Also, the syringe shown in the drawings may be used as a truepiston-type syringe by reciprocating the piston 6 with the stem 10 andbulb 12 full of liquid at all times, e.g., by the bulb action, so thatthey act as a solid piston shaft. This is effective to expel liquid outof and draw liquid into the interior 44 of the barrel 4 through nozzleopening 7.

Thus, if the operator, in applying the syringe to the patient, findsthat the bulb procedure, as described aforesaid, does not provide avigorous enough action he can utilize the piston type procedure, asaforesaid, without the necessity of securing another syringe.Furthermore, if he, at the beginning, believes that a more vigorous typeof irrigation is in order but finds that the action is too vigorous, hecan utilize the less vigorous bulb type procedure, as aforesaid, withoutsecuring another syringe.

Also, the combined bulb and piston arrangement of the invention providesa much greater total liquid capacity without adversely increasing theoverall bulk and size of the syringe by filling the barrel 4, the bulb12 and the hollow stem with the stern fully retracted during theirrigation procedure.

However, most importantly, in operating the syringe 2 as a piston-typesyringe, by reciprocating the piston 6, stem 10 and bulb 12 unit in thebarrel with the bulb 12 and stem it) initially empty or partially fullof liquid, a wide gradient of controlled, cushioned and graduallyapplied maximum median pressures and suctions can be achieved betweenthe relatively high, positive unyielding pressures and suctions achievedwhen the syringe is operated as a pure piston-type syringe, asaforesaid, and the milder pressures and suctions achieved by operatingthe syringe as a pure bulb-type syringe, as aforesaid.

The particular maximum median pressure and suction achieved can becontrolled by controlling the degree to which the stem 10 and bulb 12are initially filled with liquid between empty and full.

By operating the syringe in this way, only that pressure or suction isgradually built up which is required to overcome the resistance in thebody cavity and no more. A cushioning effect is achieved to cushion orabsorb in a controlled manner excess pressures and suctions which mightbe developed by movement of the piston to thereby prevent thedevelopment of sudden uncontrolled excess pressures and suctions. Ineffect, excess pressures and suctions are dissipated at a controlledrate. Regardless of how much resistance there is to flow through thenozzle opening 7 and regardless of the magnitude and rate of movement ofthe piston within reason, the pressures and suctions developed by suchmovement can only be built up gradually at a controlled rate. On theother hand, there is no interference with free flow of liquid into andout of the body cavity where there is no obstruction causing flowrestriction.

These advantages achieved by the aforesaid piston-type operation with aninitially empty or partially full stem and bulb are made possible by (l)the entrapped dead air cushion spaces 42 and 46 in the stem and bulb,respectively, (entrapped by the liquid 47 in the barrel as shown in H6.4) and (2) the orifice or reduced passage 30 providing communicationbetween such spaces and the syringe barrel interior 44 and reducednozzle opening 7.

This permits positive or negative pressure from the piston action toescape or bleed or overflow through the orifice 30 into the deadairspaces 4246 at a rate dependent on the size of the orifice 30, tothereby cause a gradually increasing gradient of pressure or suctionbuildup in the dead airspaces (by compression or decompression of theentrapped air), and hence at the nozzle opening 7, as the piston ismoved, which is released when the resistance to flow in the body cavityor wound is suddenly overcome. Accordingly, this eliminates thenecessity of the doctor or nurse guessing at the proper force to beapplied to the piston to overcome such resistance and avoids harmfulsurges when the resistance is finally overcome.

By partially filling the stem and bulb with liquid to begin with, thevolume of the dead airspaces 42-46 available for compression orexpansion is proportionately reduced as compared to an initially emptystern and bulb to decrease the cushioning or absorbing effect. Byincreasing the initial amount of liquid in the bulb and stem, themaximum obstruction release pressure which is built up is increased overa shorter gradient. The same is true for suction aspiration of the bodycavity.

Accordingly, the doctor, by filling the stem and bulb more or lessbetween empty and full, can control the maximum pressures and suctionsachieved and the pressure or suction gradient differential to achievemaximum control and safety.

The time-pressure gradient achieved using the syringe as a piston-typesyringe with an initially empty or partially full stem and bulb can bevaried by varying the size of the orifice 30. By decreasing its size,the rate of bleedoff of overpressure or oversuction is reduced. Thus, byvarying orifice size, many versatile results can be achieved. it ispreferred that the size of the orifice 30 be about equal to or less thanthe size of the nozzle opening 7. Of course, if the orifice sizecontinues to be decreased, a point will be reached where the action ofthe stern and bulb begins to approach that of a solid piston shaft. Forexample, when an orifice one-half the diameter of the nozzle opening wasused, the pressure gradient for a given piston movement was increasedsubstantially. On the other hand, if the orifice is much larger than thenozzle opening, liquid will flow through the orifice into the stem andbulb, which offers the least resistance to such flow, before flowingthrough the nozzle opening until a point is reached where the entrappedair in the stem and bulb is compressed to a pressure which ex ceeds theresistance of the nozzle opening so that the aforesaid beneficialcushioning effects are not achieved during initial movement of thepiston. For example, this was noted when the orifice diameter was twicethe diameter of the nozzle opening.

Although in the drawings the lower open end of the stem 10 terminates inthe piston 6 with the orifice passage 30 in the piston, the stem mayextend entirely through the piston with the orifice 30 located at thereduced lower end of the stem (in such case it is preferred that thestem does not protrude downwardly substantially below the piston in away to substantially limit the downward movement of the piston andthereby reduce the strolre of the piston). in either case, such orificepassage 30 may be considered from a functional standpoint as beingthrough the piston. Accordingly, when reference is made herein to suchpassage through the piston both constructions are included.

Although the present invention is most suitable for medical irrigatingsyringes, as above described, the same principal can be used toadvantage with hypodermic-type syringes.

It is not intended that the invention be limited to the specificembodiments described and shown, it being apparent that othermodifications are included within the scope thereof. Rather theinvention is limited only by the scope of the appended claims.

A search of the prior art revealed the following: US. Pats. Nos.493,591; 2,698,015; 2,180,063; 1,542,777; 3,013,577; 812,686; 3,028,862;743,743; 2,847,996; 2,058,5 l6; 1,878,026 and 933,398, none of which arepertinent.

I claim:

1. A medical pressure regulating syringe comprising a cylindricalsyringe barrel having at its nozzle end a restricting opening, aresilient and flexible piston having at least one external, annularsealing rib slidable in said barrel in a fluidtight manner to draw andexpel fluid into and out of said barrel through said opening, a hollowtubular piston shaft connected to said piston for sliding movement withsaid piston and with respect to said barrel, said piston having acylindrical sidewall portion embracing a portion of the shaft, theinternal wall of said cylindrical sidewall portion having an annulargroove therein, said portion of said shaft having a reduced neck and aflange ex tending radially outwardly into said groove, said hollow shaftbeing connected with a chamber communicating with the in terior of saidhollow shaft and having a resilient and flexible wall to change thevolume of said chamber, said chamber comprising an enlarged, flexible,resilient, squeezable bulb, said shaft and bulb being integral and ofplastic, said piston having a passage therethrough providing continuousand uninterrupted communication between the interior of said hollowshaft and bulb and said barrel and opening, whereby fluid can beexpelled from said hollow stem and chamber through said passage intosaid barrel and through said opening and can be drawn into said hollowstem and chamber from said barrel and opening through said passage byflexing said chamber wall.

2. A syringe according to claim 1, said integral shaft and bulb beingformed from a resilient, flexible and elastic plastic of the groupconsisting of polyethylene, polyvinyl chloride, ethylene-vinyl acetatecopolymer, natural rubber, synthetic rubber and combinations thereof.

1. A medical pressure regulating syringe comprising a cylindricalsyringe barrel having at its nozzle end a restricting opening, aresilient and flexible piston having at least one external, annularsealing rib slidable in said barrel in a fluidtight manner to draw andexpel fluid into and out of said barrel through said opening, a hollowtubular piston shaft connected to said piston for sliding movement withsaid piston and with respect to said barrel, said piston having acylindrical sidewall portion embracing a portion of the shaft, theinternal wall of said cylindrical sidewall portion having an annulargroove therein, said portion of said shaft having a reduced neck and aflange extending radially outwardly into said groove, said hollow shaftbeing connected with a chamber communicating with the interior of saidhollow shaft and having a resilient and flexible wall to change thevolume of said chamber, said chamber comprising an enlarged, flexible,resilient, squeezable bulb, said shaft and bulb being integral and ofplastic, said piston having a passage therethrough providing continuousand uninterrupted communication between the interior of said hollowshaft and bulb and said barrel and opening, whereby fluid can beexpelled from said hollow stem and chamber through said passage intosaid barrel and through said opening and can be drawn into said hollowstem and chamber from said barrel and opening through said passage byflexing said chamber wall.
 2. A syringe according to claim 1, saidintegral shaft and bulb being formed from a resilient, flexible andelastic plastic of the group consisting of polyethylene, polyvinylchloride, ethylene-vinyl acetate copolymer, natural rubber, syntheticrubber and combinations thereof.